3,4-dihydroxybutyrate (DHBA) and 3-hydroxybutyrolactone (3-HBL) are highly useful chiral intermediates that can be used to synthesize statin-class drugs like CRESTOR® and LIPITOR®, carnitine, and other fine chemicals. The annual market for statin drugs was estimated to be $10-15 billion in 2003 and 2004, while the annual demand for carnitine (which is used as a vitamin supplement) is estimated to be several hundred metric tons. DHBA and 3-HBL can also be readily derivatized into valuable compounds like carnitine, which has an approximate $5 per gram cost and is used as a vitamin and nutritional supplement.
Currently DHBA is not commercially available, while 3-HBL costs $30-100 per gram. The high cost and low availability of these compounds increases the costs of statin drugs. Existing methods for the synthesis of DHBA and 3-HBL rely on crude, harsh chemical synthetic means, such as the harsh reduction of malic acid or the breakdown of various hexose sugars with acid. Such chemical synthetic methods produce several byproducts, necessitating the extensive purification of the DHBA or 3-HBL product. These drawbacks make chemical synthesis of DHBA and 3-HBL relatively unattractive and uneconomical.